VVT point in 20v Silvertop

[Mr Revhead]

refer to the graph above..... vvt does activate below 2000 rpm in silvertops.
i personally tested it on my car

[sergei]

I can get my silvertop to activate VVT just by taping on the throttle while on idle (I got one of those ga'y lights in same place as GTZ light which I installed when I was younger )

[Mr Revhead]

lol i put one in when i was comparing the stock ecu to my SARD one.
took it out as soon as i was finished. i used a park lamp bulb and it was too bloody bright!

[AceSniper]

hmm im sure it was lower than 2k, maybe I was idling high

[slighty_sykotic]

And 12 BTDC of timing would be causing the motor to ping its nuts off on our fuel....making the motor retard the hell out of it, hence why its sluggish at high rpm.

--Sykotic

[mister2]

There are a few myths around VVT, especially to do with equating it with VTEC. Most have been addressed in this thread, but just to add my own 2c.

VVT (in 20v's) is a switched output which changes the intake cam timing by a fixed amount. When the cam is ADVANCED (on) the engine will make more power from idle RIGHT THROUGH to around 6-7000rpm. With the cam RETARDED (off) it will make more power above 6-7000rpm, and will idle smoothly.

So essentially, the only reason that VVT is off at idle and low load is for emissions, idle quality, and economy. And it switches off at high RPM because that is where the off position makes the most power.

It is pretty easy to see on a dyno, doing plots with and without VVT.

What this means though is that it is slightly more complex to think about than VTEC, where on = woohoo! You need a ECU capable of mapping the VVT output, not only a RPM-switch.

Cheers

Nick

[Loudtoy]

You may also want to try freeing up your intake and exhaust as much as possible, i found on my old facelift 101 that the less intake and exhaust restrictions i had the more power i had especially up top. Also 12btdc is far to advanced for our fuel as someone had said. Best i've found is about half that. PS if you've got a standard exhaust leave it on there get rid of the cat only and just do the intake, the standard exhaust is probably imho the best flowing and quietest sysytem for these cars.
Oh and about the vvt, if you want to feel what kind of difference it makes with it on and off you can just unplug the vvt solenoid for a short time it's down on the front side of the block on the pully side. Try it with it unplugged and see what difference it makes

[quicklvn]

Cheers guys, I feel like a n00b now lol, I don't know too much about the workings of the cams etc.

My car has a 2 1/4 freeflow on and a pod filter so thats the restrictions gone (hopefully).

I'm planning on getting it dynoed once I put my oil catch can on and an adjustable fuel pressure reg to see what they pick up. My mates also building a diognostic computer device to pick up engine faults so i'll see what that picks up.

thanks for the help

[Mr Revhead]

20vs seem to like having the stock air box rather than a pod.
fit a K&N filter into the stock box.

adjustable fuel reg is not needed, your just wasting your $$ there and opening a door way for potential problems.

[Loudtoy]

20vs seem to like having the stock air box rather than a pod.
fit a K&N filter into the stock box.

adjustable fuel reg is not needed, your just wasting your $$ there and opening a door way for potential problems.

I disagree with the statement about the pod, so long as you do it properly and build a proper cold air box around it, have the intake pipe about 3 inch and nice madrel bend of 90 degrees leaving the pod right up behind the headlight. Will require turning the airflow meter upside down so the wires will reach and works a hell of alot better than a k&n in the standard box - about 6kw difference in my experience and thats with an el cheapo pod from a k&n panel.
Oh yeah the possible downside is you will need to move your battery to somewhere else to make room for you intake.

[Mr Revhead]

iv heard of blacktops mking a gain with open/pod filter
yours would be the first time iv heard of a gain on a silvertop

[Loudtoy]

iv heard of blacktops mking a gain with open/pod filter
yours would be the first time iv heard of a gain on a silvertop

Fair to say i had a freak one, exhaust and intake only (mind you was all my own design stuff) made 84 kw sock, 87 with exhaust and standard intake and 93 with intake and exhaust. All same dyno but different days, 93 was mid summer 84 was mid winter and 87 was somewhere in the middle. Sold the car and dyno sheets went with it as the guy who brought it mates wouldn't believe that my 101 would make slightly more than his 111 on the same dyno lol. If i still had them i could have told you the temp exactly

[vvtirep]

if you want more power top end you could get some extractors. thats if you want to pay that price???

[Mr Revhead]

youll be lucky to find some that are better than the stock ones
change the 2-1 section if anything

[quicklvn]

Yeh, I was gonna buy some yesterday but I've just heard they have sold. Would it be best to get the 2-1 section of a blacktop or custom? and how will I have to modify it to make it better?

[AceSniper]

custom
blacktop still has the squish init, but has another flexi setup (thats also used in facelift 101's)